<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>总结生命周期</title>
  <!-- 引入Vue -->
  <script type="text/javascript" src="../js/vue.js"></script>
</head>

<body>
  <!-- 准备好一个容器 -->
  <div id="root">

    <h2 :style="{opacity}">欢迎学习Vue</h2>
    <button @click="opacity = 1">透明度设置为1</button>
    <button @click="stop">停止变换</button>
  </div>
</body>

<script type="text/javascript">

  new Vue({
    el: '#root',
    data: {
      a: false,
      opacity: 1
    },
    methods: {
      stop() {
        this.$destroy()
      }
    },
    //Vue完成模板的解析并把初始的真实DOM元素放入页面后（挂载完毕）调用mounted
    mounted() {
      console.log('mounted', this);
      this.timer = setInterval(() => {
        this.opacity -= 0.01
        if (this.opacity <= 0) this.opacity = 1
      }, 16)
    },
    beforeDestroy() {
      clearInterval(this.timer)
    },
  })
</script>

</html>